Honestly, Nostradamus doesn't need reassuring facial expressions. He's coming from the French Court where smiles hide knives and a man can stab you or poison you politely after having shared a dance with your sister. He himself has a somewhat muted affect much of the time, managing at most 'politely curious' when he's not babbling about his studies. Right now, he's just dazed.

"Ingo. I am Michel de Nostredame. It is good to meet you."

And it genuinely is. This is clearly a thoughtful and caring individual.